Particularly, in medical fields such as a clinical site, it is necessary to detect a cell infected with a pathogen or a cell having a predetermined mode from many cells. For example, WO 2010/027003 discloses a technique of rapidly, simply, and accurately detecting the cell. In the technique of WO 2010/027003, plural micro chambers (wells) are formed on a micro chip array, and each well is filled with fluorescently-labeled cells. Each well is observed with a fluorescent microscope while irradiated with a laser beam, and thereby a specific cell that yields fluorescence is detected.
Unexamined Japanese Patent Publication No. 2006-322819 discloses a configuration in which a series of wells filled with the cells is scanned with the laser beam to detect the fluorescence yielded from the cell. In the configuration of Unexamined Japanese Patent Publication No. 2006-322819, the series of wells is formed in a circumferential direction of a disk, and a series of information pits is formed on a layer on a light incident side separated from a layer in which the well is formed, the series of information pits being formed into a track shape so as to be arranged along an array of the wells. Address information is held in the information pit.
In this configuration, the optical system for detecting fluorescence includes different light sources: one for irradiating the wells with excitation light, and the other for irradiating the information pits with laser light. The light emitted from these light sources is converged by a common object lens. The object lens is controlled so that the laser light for the information pits is focused on the information pits and follows the series of information pits (track). As a result, the excitation light is focused on the cells placed in the wells, and the array of the wells is sequentially scanned with the laser light.
The optical system further includes a light detector for detecting fluorescence generated in cells, and a light detector for receiving laser light modulated by the information pits. The output of the light detector for receiving the laser light is formed into a signal for controlling the object lens and a signal for reproducing the information stored in the information pits.
When the fluorescence is yielded from the cell irradiated with the excitation light, the fluorescence is detected by the photodetector that detects the fluorescence. A position of the well in which the cell yielding the fluorescence is accommodated is identified by positional information that is acquired from the information pit in detecting the fluorescence. The existence or non-existence of a detection target cell and the position of the well in which the cell is accommodated are automatically detected from many cells accommodated in the series of wells provided on the disk without the fluorescence microscope observation.